From ff53ef5e3751fc0e9ba4b9a327e65df2c02de411 Mon Sep 17 00:00:00 2001 From: Tom Lane Date: Mon, 26 May 2025 15:23:32 -0400 Subject: [PATCH v4 5/5] Avoid leak when dblink_connstr_check() fails. dblink_connect() leaked the already-allocated remoteConn struct in this case. We can improve matters by just doing that allocation a bit later. There remain leakage opportunities, such as OOM inside createNewConnection(), but at least they're not reached while valgrind'ing the regression tests. Author: Tom Lane Discussion: https://postgr.es/m/2976982.1748049023@sss.pgh.pa.us --- contrib/dblink/dblink.c | 19 ++++++++++--------- 1 file changed, 10 insertions(+), 9 deletions(-) diff --git a/contrib/dblink/dblink.c b/contrib/dblink/dblink.c index 1e1baf68635..5347bf74087 100644 --- a/contrib/dblink/dblink.c +++ b/contrib/dblink/dblink.c @@ -288,15 +288,6 @@ dblink_connect(PG_FUNCTION_ARGS) else if (PG_NARGS() == 1) conname_or_str = text_to_cstring(PG_GETARG_TEXT_PP(0)); - if (connname) - { - rconn = (remoteConn *) MemoryContextAlloc(TopMemoryContext, - sizeof(remoteConn)); - rconn->conn = NULL; - rconn->openCursorCount = 0; - rconn->newXactForCursor = false; - } - /* first check for valid foreign data server */ connstr = get_connect_string(conname_or_str); if (connstr == NULL) @@ -309,6 +300,16 @@ dblink_connect(PG_FUNCTION_ARGS) if (dblink_we_connect == 0) dblink_we_connect = WaitEventExtensionNew("DblinkConnect"); + /* allocate rconn, if needed, as late as possible */ + if (connname) + { + rconn = (remoteConn *) MemoryContextAlloc(TopMemoryContext, + sizeof(remoteConn)); + rconn->conn = NULL; + rconn->openCursorCount = 0; + rconn->newXactForCursor = false; + } + /* OK to make connection */ conn = libpqsrv_connect(connstr, dblink_we_connect); -- 2.43.5